The present invention relates to a substrate support for supporting a substrate to be processed in a vacuum processing chamber, the substrate support comprising a frame for carrying the substrate, and at least a first fastening means fixedly attached to the frame for aligning the substrate relative to the frame by attaching the substrate to the first fastening means. Furthermore, the invention relates to a substrate processing device for processing a substrate, the processing device comprising at least one process chamber, processing tools arranged in the process chamber for processing the substrate, and an edge exclusion projecting over a portion of the substrate surface of a substrate supported in a substrate support and received in the process chamber for preventing processing of a portion of the substrate. Moreover, the invention relates to a method of placing a substrate on a substrate support.
In the field of processing, e.g. coating, substantially large-size plane substrates, various processing methods are used, e.g. PVD (physical vapor deposition) like sputtering, CVD (chemical vapor deposition), PECVD (plasma enhanced chemical vapor deposition), etc. By applying these processes, single layers or multi-layer systems are deposited on glass substrates to produce coated panels, display screens, OLED (organic light emitting diode) panels, thermally insulating glass panels, etc.
Generally, the layer deposition may be provided in static or in dynamic coating processes. In static coating processes, the substrate is positioned on a substrate supporting platform to be coated within a vacuum coating chamber. The substrate is secured to a support platform within a deposition chamber by clamp springs or a clamp frame while being coated.
In order to prevent deposition of particles on the edge or on the underside of the substrate, the substrate holder may include an edge exclusion or shadow frame for preventing processing of a perimeter portion of the (upper) substrate surface. A particular shadow frame supported on a shadow frame support within the cavity of a processing chamber is disclosed in U.S. Pat. No. 6,773,562 B1, which is incorporated herein by reference for all purposes. By providing the shadow frame, processing gases and plasma are prevented from reaching the edge and the backside of the substrate.
In dynamic coating processes, the substrate is fixedly attached to a carrier in order to provide the transport and transfer of the substrate between the various handling and processing chambers. Usually, the carrier comprises a frame extending along the edge of the glass substrate. The glass substrate is fixed in the carrier by clamp springs. During the deposition of coating particles on the substrate, particles may also be deposited on the frame causing particle problems. Particularly, when the carrier is locked in, locked out and transported between various coating chambers, it may be heated up and cooled down at frequent intervals. Due to thermal expansions of the carrier, the glass substrate has no defined position relative to the carrier during the processing/coating steps.
A number of problems have been identified with respect to the handling and processing of large-size substrates. Particularly, in a static process, the transport of glass substrates is difficult and the substrate may be damaged, e.g., by displacement of the substrate arranged on the supporting platform when positioning and aligning the substrate. Furthermore, if the edge exclusion is not properly centered relative to the substrate during the processing steps, the amount of shadowing will be unequal and inexact. Particularly, when depositing a number of layers in different chambers, re-positioning of the substrate may be required after moving the substrate from one processing chamber into the next processing chamber.
In dynamic coating processes, an exact positioning of the substrate relative to the carrier (and possibly relative to a shadow frame) is difficult to maintain during the complete process.